2489 dual absorbance detector

The concentration of fluconazole in the test solutions was analyzed using an HPLC system that consisted of Waters 1525 binary pumps, 2489 dual absorbance detector, and Waters Breeze Software 2.0 versions (Waters Corporation, Milford, MA, USA). A C-18 reversed-phase HPLC column (4.6 mm × 150 mm) with a 5-μm particle size packing material (Mightysil RP-18 GP, Kanto Chemical Co., Inc., Tokyo, Japan) was used. The mobile phase was acetonitrile:water (30:70) with a flow rate of 1 mL min⁻¹. The detection wavelength was set at 210 nm. The retention time of fluconazole was approximately 2.8 min. Under these conditions, good linearity and reproducibility were demonstrated over the 20–60 μg mL⁻¹ fluconazole range. The limit of detection and limit of quantification, which were determined and computed using a linear regression curve [20 (link)], were found to be 18.22 and 55.21 µg mL⁻¹, respectively. Additionally, the relative standard deviations of the intra-day and inter-day variations of the fluconazole peak area at the concentrations of 20 and 40 µg mL⁻¹ were less than 1 and 2%, respectively.

Cysteine, glutathione, and methionine were analyzed in roots by HPLC-technique using Empower3™ software (Waters Corporation, Milford, MA, USA). The chromatography system was connected to a C18 reverse phase-HPLC column (pore size: 300 A, particle size: 5μm, pH range: 1.5–10, dimension: 250 mm × 10 mm) was supplied with buffer A (0.1% TFA and water) and buffer B (0.1% TFA and 80% acetonitrile) at the gradient of 1–24 min 100% A, 25–34 min 100% B and 35–40 min 100% A as mobile phase. Prior to injection, the samples and standards were diluted (100×) and filtered using 0.22 μm Minisart Syringe Filters (Finetech, Taichung, Taiwan). S-metabolites were detected at 280 and 360 nm with a Waters 2489 dual absorbance detector [56 (link)].